Horses for courses, I guess. Fusion 360 has a very powerful CAM package that knows about dovetail tools, and lets you define your own if there isn't something in the library to match what you have. So F360 could do the job. I might do it that way (my machine is built to take vertical panels at the end of the machine, although couldn't quite manage 8' panels...) if I were just doing a one-off, but I could understand why someone might want a better package optimised for this specific job if they were doing it at all often. I could do V engraving CAM with F360, but it's a whole lot easier with vCarve. At a price, of course. I have tried to use F360 for some relatively complex slot-together tab-and-slot panels but it was hard work, even with a special plug-in, to add dog-bone fillets in the internal corners. I ended up designing the tab-and-slot panels in F360, then writing out the DXF designs, importing into vCarve, and using that for the fillets.

Powerful-but-complex, specialised-but-straightforward? I think you have to try the options and see what works for you. Especially if this is going to be part of a money-making process. A friend who runs a small sign-making business cheerfully bought vCarve; the £400 or so it cost will pay for itself in saved time in just a few jobs compared to "free" software. Gerry's software looks quite good against that. Ho hum - we all have to choose our own ways forward.

The Leigh jig has templates for some really strange-looking "dovetail" interlocking joints. Not sure how many of them are possible with CNC...